Besides using Type II cement, what is another method to manage heat of hydration in large pours?

• A. Increasing water content
• B. Cooling the mix
• C. Accelerating curing
• D. Adding more aggregate

Answer: (B)

When a pour is large, the heat released as cement hydrates can raise the concrete temperature faster than it can dissipate, risking thermal cracking. Using cement with lower heat of hydration (like Type II) helps, but another effective approach is cooling the mix to start with a lower temperature.

Cooling the mix works by lowering the temperature of the materials before and during mixing—think chilled water or ice added to the mix, cooled aggregates, or other cooling methods. This directly reduces the temperature rise as hydration proceeds, helping keep internal temperatures within safer limits and reducing thermal stress.

Increasing water content would actually raise the heat and can weaken the final concrete; accelerating curing tends to speed up hydration and increase early heat; adding more aggregate doesn’t reliably reduce the heat of hydration. Cooling the mix is the targeted method to limit the heat rise in large pours.